Offshore terminal with underwater foundation

ABSTRACT

In an offshore terminal with underwater foundation and underwater pipeline leading from the shore to the foundation, a tower in which a pipe runs up, from the pipeline to connecting facilities at the top; the tower has floatation tanks and is hinged to the foundation for selective erection, whereby the top of the tower projects above the waterline, and for folding down for the tower to lie on the ocean floor. The bottom of the tower when erected, being releasably locked to the foundation.

United States Patent u l Dutta et al.

[451 Apr. 2', 1974 1 1 OFFSHORE TERMINAL WITH UNDERWATER FOUNDATION [75] lnventorsi Dipak Dutta, Dusseldorf-Rath;

Karl-Gerd Wurker, Hosel, both of Germany [73] Assignee: Mannesmannrohren-Werke Aktiengesellschaft, Dusseldorf, Germany [22] Filed: Mar. 29, 1972 [21] Appl. No.: 239,236

[52 US. Cl 61/46, 61/48, 141/387 [51] Int. Cl E02b 3/20, E02d 27/52 [58] Field of Search 61/46, 46.5, 48; 114/230;

[56] References Cited UNITED STATES PATENTS 2,955,626 10/1960 Hartley 141/279 Miller 61/46 X Bea (ml/46.5

Primary Examiner-Jacob Shapiro Attorney, Agent, or FirmSmith,-Roston & Pavitt [57] ABSTRACT In an offshore terminal with underwater foundation and underwater pipeline leading from the shore to the foundation, a tower in which a pipe runs up, from the pipeline to connecting facilities at the top; the tower has floatation tanks and is hinged to the foundation for selective erection,,whereby the top of the tower projects above the waterline, and for folding down for the tower to lie on the ocean floor. The bottom of the tower when erected, being releasably locked to the foundation.

2 Claims, 4 Drawing Figures PATENIEDAPR em 3.800.547

SHEET 1 (IF 2 PATENTEDAPR 2:914

sum 2 [1F 2 Fig.)

OFFSHORE TERMINAL WITH UNDERWATER FOUNDATION BACKGROUND OF THE INVENTION The present invention relates to equipment for off-. shore loading and unloading of tankers. More particularly, the invention relates to improvements in such terminals which include a tower anchored to the bottom of the sea, but projecting above sea level; an underwater pipeline runs to that tower and connects to a pipe that runs up in the tower for connection to anoil transfer line ofa tanker. The pipe connection is usually closable in between oil transfers.

The simplest form of such terminal includes a tower rammed into the ocean floor in one form or another. However, such a tower construction exhibits two significant disadvantages. The stationary tower is continuously subjected to the pounding forces of the sea and its life is accordingly short. This is particularly so, if the tower stands quite high in relatively deep waters, because the terminal is to accommodate low-lying high tonnage tankers. On the other hand, if such a terminal is positioned in the vicinity ofa harbor or close to main shipping routes, the tower constitutes an ever present danger.

Other offshore terminals are constructed as floating buoys, following to some extent the motion of a moored tanker. However, the floating terminal facility has to be anchored in some form to the ocean floor, so that such a terminal is exposed to the forces of the ocean. When the sea is heavy, it becomes quite difficult to connect a tanker to the terminal. Of course, such floating terminals constitute also possible hindrances for ships, even more so, if the anchoring chain runs obliquely due to heavy current and possibly varying in direction making the location of the chain unpredictable.

SUMMARY OF THE INVENTION Is is an object of the present invention to provide an offshore terminal construction offering the advantage of an artificial island, but being protected against heavy seas, particularly when not needed; i.e. when there is no ship to take on or to deliver cargo.

In accordance with the preferred embodiment of the present invention, it is suggested to provide for an underwater foundation, possibly flush with the ocean floor. A tower is hinged to that foundation. When in upright position, the top of the tower with delivery equipment etc., projects above the sea level. This can be termed the operating position of the terminal. The tower can be tilted about the hinge or pivot axis, to lie more or less flat on the ocean floor when not needed. Thus, the tower serves as a terminal only when needed; at other times it is pivoted out of the way for its own protection as well as for reasons of safety of traffic close by.

The pivotal link between foundation and tower may be operated by remote control in that locking means are provided opposite the pivot or hinge and which are unlocked for pivoting the tower down. The erection and folding down of the tower may be controlled through floatation chambers disposed along the tower and flooded or blown on command.

While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention, it is believed that the invention, the objects and features of the invention and further objects, features and advantages thereof will be better understood from the following description taken in connection with the accompanying drawings in which:

FIG. 1 shows an offshore terminal constructed in accordance with the preferred embodiment of the invention and illustrated in errected, operating position of its tower;

FIG. 2 shows the same tower lying down;

FIG. 3 illustrates a detail of the top of the tower; and

FIG. 4 illustrates the underwater locking mechanism at the bottom of the tower.

DETAILED DESCRIPTION OF THE DRAWINGS Turning first to FIG. 1, a tower 3 is shown to be positioned on a bed or foundation 7 in the ocean floor 1. The foundation is underground and flush with the ocean bottom; The tower 3 is shown in erected, upright or standing position, so its upper part projects above the sea level 2. Tower 3 is pivotally linked to a hingelike joint 4; the opposite side of the tower stands on the foundation 7 and is connected thereto by locking device 5. Hinge 4 and locking device 5 secure tower 3 to foundation 7. i

Floatation chambers or tanks 6 are disposed along the tower construction. These chambers will be flooded for pivoting the tower down, while blowing the tanks 6 will cause the tower to swing up.

An underwater pipeline 9 runs from shore facilities to the foundation 7 of this offshore terminal. Pipeline 9 connects to a pipe 10 which runs up in tower 3 and terminates in-an outlet 10a. As shown in FIG. 1, a hose 11 connects pipe outlet 10a to a tanker 12, which is tied to the terminal (top of tower 3) by means of ropes 13 or the like.

FIG. 2 illustrates the tower when folded down, whereby a support arm 14 or the like at the top of the tower rests on a sunken base 8, provided for that purpose. In that sense, the tower lies on the ocean' floor. The dash dot lines in FIG. 2 show an in-between position 3' of the tower when lowered or erected.

Turning joints are provided for connecting the pipeline 9 to pipe 10. One turning point is needed, of course, for permitting the pipe 10 to follow the pivot motion of the tower about the horizontal hinge axis. Another turning joint acting transversely to the first one is needed for the pipe to follow any relative motion of the vessel 12 on a vertical axis around the tower during cargo transfer.

FIG. 3 shows in greater detail the top of tower 3. A platform 31 is provided here for supporting a turntable 15. Bollards 16 are mounted on turntable 15, to serve as mooring posts for ships. The turning joint on pipe 10, permitting turning of the upper end about a vertical axis (for erected tower) may be provided in the turntable l5.

FIG. 4 illustrates that bottom portion of tower 3, which is to be locked or latched to the underwater foundation 7 as long as the tower is to stand erected. A latching nose 17 at the bottom of tower 3 engages a holding arm or nose 18 of the locking mechanism. If the tower swings into upright position, the curved position of nose l7 forces nose 18 out of the way, against the latching force of a spring 19 which biases the nose 18 in forward or protracted direction. As soon as nose 17 has cleared nose 18, the latter snaps forward by operation of expanding spring 19, and nose l8 latches nose 17, thereby locking the tower in erected position.

The lock or latch is unlocked as follows. A remote controlled motor turns a disk 21 to which is excentrically and pivotally linked one end of a rod 20. The other end of rod 20 connects to nose 18. As the motor turns disk 21 (counterclockwise in the Figure), rod 20 retracts the nose 18 so as to release nose 17. As tanks 6 are flooded, the tower will pivot down. The rate of flooding will control the degree of gentleness of folding. After folding has begun, the motor will reverse for nose 18 to protract. The motor may be used as lock aid, when the tower is about to be erected, so that compression of spring 19 does not have to be provided for exclusively through buoyancy control in the last phase of tower erection.

The invention is not limited to the embodiments described above but all changes and modifications thereof not constituting departures from the spirit and scope of the invention are inteded to be included.

We claim:

1. In an offshore terminal with underwater foundation and underwater pipeline leading from the shore to the foundation, and a tower in which a pipe runs up, from the pipeline to connecting facilities at the top of the tower, having a multisided structure and including spaced first and second opposite sides, each side having a top and a bottom respectively pertaining to top and bottom of the tower the improvement comprising;

means on the foundation for hinging the bottom of the first side of the tower to the foundation and provided for selective erection of the tower, whereby the top of the tower projects above the waterline, and for folding down of the tower so that the tower may lie on the ocean floor;

first latch nose means on the bottom of the second side of the tower;

Second latching nose means on the foundation and having disposition to the first latch nose means for releasably locking the bottom of the second side of the tower to the foundation when the tower is in upright position; and

reversing means for retracting one of the latch nose means from the respective other one to release the first nose means from the second latch nose means to permit folding down of the tower, and for protracting the one latch nose means to restore the locking of the tower when in the upright position.

2. In a terminal as in claim 1, the tower equipped with floatation tanks for folding the tower up or down. 

1. In an offshore terminal with underwater foundation and underwater pipeline leading from the shore to the foundation, and a tower in which a pipe runs up, from the pipeline to connecting facilities at the top of the tower, having a multisided structure and including spaced first and second opposite sides, each side having a top and a bottom respectively pertaining to top and bottom of the tower the improvement comprising; means on the foundation for hinging the bottom of the first side of the tower to the foundation and provided for selective erection of the tower, whereby the top of the tower projects above the waterline, and for folding down of the tower so that the tower may lie on the ocean floor; first latch nose means on the bottom of the second side of the tower; Second latching nose means on the foundation and having disposition to the first latch nose means for releasably locking the bottom of the second side of the tower to the foundation when the tower is in upright position; and reversing means for retracting one of the latch nose means from the respective other one to release the first nose means from the second latch nose means to permit folding down of the tower, and for protracting the one latch nose means to restore the locking of the tower when in the upright position.
 2. In a terminal as in claim 1, the tower equipped with floatation tanks for folding the tower up or down. 